Call Centre Shrinkage: What It Is, Why It Matters & How to Calculate It

What is Call Centre Shrinkage?

Call centre shrinkage is the proportion of agent time lost to non-queue activities or absence. It’s expressed as a percentage of total paid time. In practice, shrinkage explains why “we rostered 100 people” turns into “we only had 82 actually taking calls”.

Rule of thumb: If you don’t plan for shrinkage, your plan isn’t a plan — it’s a wish.

Types of Shrinkage

There are two main categories of call centre shrinkage that WFM teams monitor and manage. Understanding the difference between planned and unplanned shrinkage is essential for accurate forecasting, targeted action plans, and realistic staffing models. By tracking both separately, you can identify the biggest drivers of lost time and develop strategies to reduce their impact.

• Planned Shrinkage: Activities you can schedule and forecast:
  • Paid breaks and lunches
  • Team meetings and huddles
  • Training and coaching
  • Annual/paid leave
  • Project or back-office work
• Unplanned Shrinkage: The surprises that punch holes in your day:
  • Sick leave and personal emergencies
  • Unscheduled breaks / lateness / early finishes
  • IT or telephony outages
  • Ad‑hoc escalations, rework, or compliance locks

Why Shrinkage Matters

Understanding why call centre shrinkage matters is critical for every Workforce Management (WFM) leader, team manager, and operations director. Shrinkage isn’t just a number on a report — it’s the hidden factor that determines whether your contact centre can meet demand, hit service levels, and control costs.

If you don’t account for it, even the most accurate volume forecasts will fail, leaving customers waiting longer, agents under pressure, and the business paying more to recover.

• Meeting Service Levels: Shrinkage reduces the number of people actually available to take calls, answer chats, or respond to messages. If you don’t factor it in, you’ll roster too few people — leading to longer wait times, missed SLAs, and frustrated customers.
• Managing Costs: Ignoring shrinkage can force you into expensive fixes like overtime, last-minute casual hires, or diverting staff from other work. Building it into your plan keeps budgets stable and predictable.
• Protecting Your Team: Under-staffing caused by unplanned shrinkage puts more pressure on the people who are working. That stress often leads to burnout, absenteeism, and higher turnover — which in turn makes shrinkage even worse.

How to Calculate Call Centre Shrinkage

Calculating call centre shrinkage is about working out what percentage of your total paid staff time is lost to things other than handling customer contacts. There are two ways to look at it — and they both give the same result:

• Time-based calculation: Compare the total minutes paid with the minutes actually available for customer work.
  Shrinkage % = (Time Not Available ÷ Total Paid Time) × 100
• Headcount-based calculation: Compare how many people you need to meet demand with how many are actually available.
  Shrinkage % = ((Required Staff − Available Staff) ÷ Required Staff) × 100

Example: Let’s say your forecast says you need 50 agents available to meet your service level. After factoring in breaks, leave, training, and absenteeism, you only have 40 ready to take contacts. That’s:
((50 − 40) ÷ 50) × 100 = 20% shrinkage.

When building rosters, you can flip the formula to work out how many people to schedule:
Scheduled = Required ÷ (1 − Shrinkage)
In this example, with 20% shrinkage (0.20) and 40 needed, you’d schedule:
40 ÷ 0.8 = 50 agents.

Get this calculation wrong and you’ll almost always under-staff — which means longer queues, stressed agents, and unhappy customers.

Free Call Centre Shrinkage Calculator

How to Reduce Shrinkage

To reduce call centre shrinkage, treat it as a operational problem you can diagnose and control — not a mystery. Separate planned and unplanned shrinkage, measure them monthly (and by interval where possible), then target the biggest drivers with specific actions: smarter scheduling, tighter adherence, fewer outages, and better attendance. Feed the realised numbers back into your next roster so improvements actually stick.

• Split the problem: Track planned vs unplanned shrinkage separately. Target the bigger bucket first.
• Schedule smart: Avoid loading meetings/training into peak demand windows. Use micro‑coaching in quiet intervals.
• Tighten adherence: Clear start/finish rules, realistic break spacing, and supportive leadership (not surveillance theatre).
• Improve attendance: Wellbeing programs, fair workloads, flexible rosters, and early intervention reduce sick leave.
• Harden tech: Invest in reliability — outages are hidden shrinkage with very public consequences.
• Close the loop: Feed realised shrinkage back into forecasts and hiring plans every month.

FAQ: Quick Answers

• What’s a “good” shrinkage number? Context matters. Many centres land between 28%–35% when you include leave, breaks, meetings, and typical unplanned loss. Your mileage will vary.
• Does shrinkage include paid breaks? Yes. If an agent isn’t contact-available, it’s shrinkage — regardless of the reason.
• Does shrinkage include unpaid lunch? No. Shrinkage is calculated on paid time only. If lunch is unpaid, it’s excluded from the calculation.
• Should I use the same shrinkage all year? No. Seasonality, leave patterns, and training cycles change it. Track monthly at minimum.
• Is shrinkage the same as occupancy? No. Occupancy measures how busy available agents are. Shrinkage measures how much paid time they’re not available at all.
• Does shrinkage differ between channels? It can. Phone, email, chat, and social media have different interruption patterns, but shrinkage is still staff-based. If agents work across multiple channels, their shrinkage applies to their total paid time — not per channel — unless you measure each channel with its own dedicated FTEs.
• What’s the difference between planned and unplanned shrinkage? Planned shrinkage is predictable (leave, training, meetings). Unplanned is unexpected (sick leave, outages, urgent escalations).
• Can shrinkage be negative? Rarely. It happens if “available” time exceeds “required” time — usually from overstaffing against actual demand.